As you may remember, I’ve designed a universal platform for building retro-computers “Retrobyte”. I have successfully tested it by building the “Mikro-80” computer a few months ago and now I’m working on adapting my other retro-computer project “AGAT-7” to this platform. “AGAT-7” requires more functionality than “Retrobyte” has, so I’ve build an extension board for[…]

I’m about to finalise my Rev.0 of the modern replica of the retro-computer “AGAT-7”. The next step will be Rev.A design with fixed mistakes, improvements and some new ideas. In this post I’m going to summarise the Rev.0 experience and share with you with some ideas for Rev.A. At the moment the Rev.0 computer starts[…]

Let’s go to the following part of the schematic. Today it is the CPU, the SRAM and the joysticks. Here it is: “Agat-7” has 96Kb of RAM, so we need 128Kb SRAM chip. We can use 128K x 8bit or 64K x 16bit chips. The second option requires 9 more FPGA pins to connect but[…]

At the moment I’ve completed the schematics and I’ve started to work on PCB layout. There are going to be some changes caused by discovered mistakes or better layout. So, please, treat it as a draft on this stage. Please, let me know if you notice any mistakes. Today we will have a look at[…]

I’ve spend some time to debug STM32L based 140K “floppy-drive” for my “Agat-7” replica project. It is already perfectly workable in read only mode. I transferred it to SPI interface to save some FPGA pins and now I need only 5 pins instead of 12. For 840K floppy drive it will save even more pins.[…]

In this post I’m going to show what has been done in the project. First of all, an extension board for DE1, that contains a socket for 6502 CPU, was made. I used a toner transfer method to make a PCB. The board connects straight to GPIO0 header on DE1 board: CPU doesn’t require all[…]

Lets discuss the concept of the replica of Agat-7 computer. This version is not final and can be (and most likely will be) adjusted. As usual, all your ideas are welcome! CPU. A Bulgarian 6502 clone CM630 will be used as CPU in the project. But it can be changed to any other 6502 clone[…]

After the trial project of the “UT-88′ computer, lets start with a much more serious project. We will design and build another Soviet computer – AGAT-7. In this case the DE1 board will be used only for prototyping – the computer will be built on its own board. So, lets see what this computer was.[…]